Thermal insulating foamed material, method for producing the same, and thermal insulating cabinet

ABSTRACT

There are disclosed a thermal insulating foamed material, which is superior in thermal insulating property and does not cause deterioration of the thermal insulating property with a time lapse, and a method for producing the same. According to a method for producing a thermal insulating foamed material, a foamed polyurethane resin composition having closed cells, in which at least carbon dioxide is filled, is formed by blowing a raw material mixture containing epoxides comprising at least two members of an epoxide compound having high reactivity with carbon dioxide and an epoxide compound having low reactivity with carbon dioxide, a carbon dioxide fixation catalyst, polyisocyanate, a reactive blowing agent which evolves carbon dioxide by reacting with said polyisocyanate, and a polyol composition. Then, the carbon dioxide in the closed cells is allowed to react with the epoxides in the presence of the carbon dioxide fixation catalyst, thereby to fix carbon dioxide as carbonate compounds.

TECHNICAL FIELD

The present invention relates to a thermal insulating foamed materialwhich is used for a refrigerator, freezer and the like, a method forproducing the same, and a thermal insulating cabinet filled with thethermal insulating foamed material.

BACKGROUND ART

A thermal insulating foamed material of a foamed urethane resin whereina blowing is performed by evaporating a blowing agent in the reactionprocess has hitherto been produced by mixing a polyol compositioncontaining a blowing agent, a foam stabilizer and an urethane reactioncatalyst with polyisocyanate with stirring.

Recently, environmental pollution or disruption such as depletion ofozone layer or global warming by chlorofluorocarbons (hereinafterabbreviated to "CFC") or hydrochlorofluorocarbons (hereinafterabbreviated to "HCFC") has been a social problem, and thus a reductionin or a complete abolishment of the use of specific CFC substances suchas trichloromonofluoromethane (CFC-11), which is a blowing agent, hasbeen contemplated. Therefore, a substance almost free from environmentalpollution or disruption, for example, 1,1-dichloro-1-fluoroethane(HCFC-141b), 1,1-dichloro-2,2,2-trifluoroethane (HCFC-123) andhydrocarbon (hereinafter abbreviated to "HC") such as cyclopentane hasbeen used as the blowing agent. However, a reduction in amount of HCFCused has been proceeded because HCFC has an ozone depletion coefficient.A HC blowing agent has a vapor thermal conductivity larger than that ofconventional CFC-11, thereby to increase a thermal conductivity of theresultant polyurethane foamed material.

When the polyurethane foamed material is produced using theabove-mentioned compound as a volatile blowing agent, water is used as areactive blowing agent for the purpose of improving the blowingefficiency, in addition to the volatile blowing agent. In that case,carbon dioxide produced by the reaction between water and polyisocyanateexists in the closed cells of the polyurethane foamed material, inaddition to a vapor of the volatile blowing agent. That is, water addedreacts with an isocyanate group and the volatile blowing agent isevaporated by reaction heat, thereby to perform blowing. In addition,blowing is also performed by carbon dioxide evolving as a result ofreaction between water and the isocyanate group. Even if water is notadded, carbon dioxide evolves by the carbodiimide reaction wherein apart of isocyanate groups reacts with each other. However, the vaporthermal conductivity of carbon dioxide is generally higher than that ofthe volatile blowing agent. Therefore, there is a problem that carbondioxide exists in the closed cells and a thermal insulating property ofthe polyurethane foamed material is deteriorated when a ratio of carbondioxide in vapor increases.

In order to improve the thermal insulating property of the polyurethanefoamed material, a trial of decreasing the proportion of carbon dioxidein the closed cells has hitherto been made. There is a proposal toimprove the thermal insulating property of the polyurethane foamedmaterial by fixing carbon dioxide having a poor thermal insulatingproperty, which exists in the closed cells (Japanese Laid-Open PatentPublication Nos. Hei 7-53757 and Hei 7-173314). When using thistechnique, only carbon dioxide exists in the closed cells in the case ofusing water alone as the blowing agent and the inside of the closedcells becomes a vacuum state by fixing this carbon dioxide, thereby toimprove the thermal insulating property. When using a volatile blowingagent having a low vapor thermal conductivity, the closed cells arefilled with carbon dioxide, produced by the reaction between water addedand the isocyanate group or carbodiimide reaction, and a vapor of thevolatile blowing agent as mentioned above. Then, only the vapor of thevolatile blowing agent having a low vapor thermal conductivity remainsin the closed cells by fixing carbon dioxide, thereby to improve thethermal insulating property.

For example, in the proposal by Japanese Laid-Open Patent PublicationNo. Hei 7-173314, an epoxide compound and an addition reaction catalystare previously added to a blowing stock solution and, after forming afoamed thermal insulating material, the epoxide compound reacts withcarbon dioxide to form a cyclic carbonate compound, thereby to fixcarbon dioxide. It is characterized in that the partial pressure ofcarbon dioxide inside the closed cells is reduced by this to reduce thevapor thermal conductivity, thereby to improve a thermal insulatingproperty.

In the polyurethane foamed material, a primary reaction between waterand polyisocyanate and that between polyol and polyisocyanate generallyproceed at the blowing stage. After forming the foamed material,polyisocyanate and water partially remain sometimes. Therefore, thebetween water and the isocyanate group or carbodiimide reaction whereinthe isocyanate groups react with each other occur gradually with a timelapse and carbon dioxide evolves and gradually increases a ratio ofcarbon dioxide in the closed cells, thereby to deteriorate the thermalinsulating property with a time lapse sometimes. In the foamed thermalinsulating material whose thermal insulating property is improved byfixing carbon dioxide to reduce the partial pressure of carbon dioxide,as shown in the construction of the above-mentioned proposal, a changein partial pressure due to evolution of carbon dioxide with a time lapseis particularly large. Therefore, there arose a problem that an increasein thermal conductivity becomes remarkable, thereby to drasticallydeteriorate the thermal insulating property.

In the construction of the above-mentioned proposal, the primaryreaction between water and the isocyanate group and that between polyoland polyisocyanate proceed at the blowing stage and, at the same time,side reactions such as polymerization of the epoxide compound andpolyisocyanate, polymerization of the epoxide compound and polyol,polymerization of the epoxide compounds, etc. proceed competitively. Thereaction between the epoxide compound and polyisocyanate is exclusive asthe primary side reaction, and the epoxide compound partially serves asa curing agent of a foamed urethane resin composition, which becomes apart of the resin component. Accordingly, the resin component of theresultant polyurethane foamed material has a structure wherein aurethane resin and an epoxy resin are combined with each other.Therefore, when epoxide compounds having a small amount of functionalgroups become a part of the resin component due to the side reactionthereof, a resin thermal conductivity of the thermal insulating foamedmaterial becomes high by exerting an influence thereof. Even if carbondioxide is removed by fixation, a reduction effect of the vapor thermalconductivity is not sufficiently exhibited sometimes. On the other hand,it is also considered to use a polyfunctional epoxy resin raw materialhaving a comparatively large molecular weight as the epoxide compound,as a means for inhibiting the resin thermal conductivity fromincreasing. However, it is assumed that the vapor thermal conductivitycan not be sufficiently reduced because a fixation property of carbondioxide is deteriorated.

Furthermore, an activity of the reaction between the epoxide compoundand polyisocyanate which is the above-mentioned main side reaction iscomparatively lower than that of the reaction between polyol andpolyisocyanate, which is the primary reaction. Therefore, a rate ofcuring due to the reaction between the epoxide compound andpolyisocyanate becomes slow. In the case of the epoxide compound havinga small amount of functional groups, a productivity is drasticallylowered sometimes, by delayed development of a mechanical strength ofthe polyurethane foamed material or extension of time up to the time ofremoving from the mold.

Accordingly, it is required to improve the thermal conductivity of thepolyurethane foamed material by rapidly fixing carbon dioxide inside theclosed cells with the residual epoxide compound without increasing thethermal conductivity of the resin in the polyurethane foamed materialdue to an inclusion of the above-mentioned side reaction product. It isalso required to improve the thermal conductivity of the polyurethanefoamed material by allowing the residual epoxy group to react withcarbon dioxide in the closed cells and carbon dioxide evolving with atime lapse even if the epoxide component becomes the resin component.

Under these circumstances, an object of the present invention is toprovide a thermal insulating foamed material comprising a foamedurethane resin composition which is superior in thermal insulatingproperty.

Another object of the present invention is to provide a method forproducing a thermal insulating foamed material having an improvedthermal insulating property, which can rapidly develop a mechanicalstrength of the resin and is superior in productivity.

DISCLOSURE OF INVENTION

The above-mentioned object of the present invention is accomplished byusing at least two members of an epoxide compound having high reactivitywith carbon dioxide and an epoxide compound having low reactivity withcarbon dioxide, as epoxides for fixing carbon dioxide.

According to the present invention, a method for producing a thermalinsulating foamed material comprises the steps of:

blowing a raw material mixture containing epoxides comprising at leasttwo members of an epoxide compound having high reactivity with carbondioxide and an epoxide compound having low reactivity with carbondioxide, a carbon dioxide fixation catalyst, polyisocyanate, a reactiveblowing agent which evolves carbon dioxide by reacting with thepolyisocyanate, and a polyol composition, thereby to form a foamedpolyurethane resin composition having closed cells in which at leastcarbon dioxide is filled, and

allowing the carbon dioxide in the closed cells to react with theepoxides in the presence of the carbon dioxide fixation catalyst,thereby to fix the carbon dioxide as carbonate compounds.

As the reactive blowing agent, for example, water, hydrogen peroxide,and a lower carboxylic acid such as formic acid are used.

The thermal insulating foamed material of the present inventioncomprises a foamed urethane resin composition having closed cells, thefoamed urethane resin composition containing a carbon dioxide fixationcatalyst and cyclic carbonate compounds as products of reactions betweencarbon dioxide and epoxides in the presence of the carbon dioxidefixation catalyst, the cyclic carbonate compounds comprising at leasttwo members of a product of an epoxide compound having high reactivitywith carbon dioxide and carbon dioxide and a reaction product of anepoxide compound having low reactivity with carbon dioxide and carbondioxide.

In one preferred embodiment of the present invention, the epoxidecompound having high reactivity with carbon dioxide is an epoxidecomplex in which the carbon dioxide fixation catalyst is coordinated toan oxirane ring.

This epoxide complex is produced by combining the epoxide compound withthe carbon dioxide fixation catalyst. That is, examples thereof includean epoxide complex in which a nucleophile is coordinated to carbon of anoxirane ring, an epoxide complex in which an electrophile is coordinatedto oxygen of an oxirane ring, an epoxide complex in which a nucleophileis coordinated to carbon of an oxirane ring and an electrophile iscoordinated to oxygen of an oxirane ring and the like.

Regarding the epoxide complex used herein, it is preferred that theamount of the epoxy group is from 0.01 to 1.0 mol per mol of the epoxygroup of the epoxide compound having low reactivity with carbon dioxide.

In another embodiment of the present invention, the epoxide compoundhaving high reactivity with carbon dioxide is an epoxide complex inwhich the carbon dioxide fixation catalyst is coordinated to an oxiranering, and the epoxide compound having low reactivity with carbon dioxideis an alkylene oxide.

In still another embodiment of the present invention, the epoxidecompound having high reactivity with carbon dioxide is an epoxidecomplex in which the carbon dioxide fixation catalyst is coordinated toan alkylene oxide, and the epoxide compound having low reactivity withcarbon dioxide comprises an alkylene oxide and a glycidyl ether.

The preferable epoxides used in the present invention contain an epoxidecompound having high reactivity with polyisocyanate and an epoxidecompound having low reactivity with polyisocyanate, and the epoxidecompound having low reactivity with carbon dioxide is an epoxidecompound having high reactivity with polyisocyanate.

It is preferred that the amount of the epoxy group of the epoxidecompound having high reactivity with polyisocyanate is from 0.50 to 2.0mol per mol of the epoxy group of the epoxide compound having lowreactivity with polyisocyanate.

A specific construction of the above-mentioned epoxides with definedreactivity with polyisocyanate will be shown below.

First, the epoxide compound having high reactivity with polyisocyanateis a polyglycidyl ether having two or more epoxy groups, and the epoxidecompound having low reactivity with polyisocyanate is a monoglycidylether having one epoxy group.

Second, the epoxide compound having high reactivity with polyisocyanateis a polyglycidyl ether having at least one hydroxyl group, and theepoxide compound having low reactivity with polyisocyanate is a glycidylether having no hydroxyl group.

Third, the epoxide compound having high reactivity with polyisocyanateis a polyglycidylamine, and the epoxide compound having low reactivitywith polyisocyanate is a glycidyl ether.

The preferable epoxides used in the present invention contain an epoxidecompound having a boiling point of more than 120° C. and an epoxidecompound having low reactivity with polyisocyanate and a boiling pointof 120° C. or less, and the epoxide compound having low reactivity withcarbon dioxide is an epoxide compound having low reactivity withpolyisocyanate.

It is preferred that the amount of the epoxy group of the epoxidecompound having a boiling point of more than 120° C. is from 0.20 to 2.0mol per mol of the epoxy group of the epoxide compound having a boilingpoint of 120° C. or less.

More preferably, the epoxide compound having a boiling point of morethan 120° C. is a glycidyl ether, a glycidyl ester or a glycidylamine,and the epoxide compound having a boiling point alkylene 120° C. or lessis an alkylene oxide.

In the preferred method for producing the thermal insulating foamedmaterial of the present invention, a volatile blowing agent is added toa raw material mixture.

In the method for producing the thermal insulating foamed material ofthe present invention, the amount of epoxides added for fixing carbondioxide is the amount having the epoxy group in an amount preferablyfrom 1 to 6 mol, more preferably from 1.5 to 4 mol, per mol of carbondioxide evolving as a result of the reaction between the reactiveblowing agent and polyisocyanate.

It is preferred that the polyisocyanate has an isocyanate group whosemolar amount is the same as that of a hydroxyl group in the raw materialmixture, and has an isocyanate group which reacts with 0 to 50% of theepoxy group of the epoxide.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a partially sectioned perspective view showing a thermalinsulating cabinet of one embodiment in accordance with the presentinvention.

FIG. 2 is a schematic view showing a construction of the thermalinsulating foamed material of the embodiment in accordance with thepresent invention.

FIG. 3 is a schematic view showing a construction of a conventionalthermal insulating foamed material.

BEST MODE FOR CARRYING THE INVENTION

The preferred embodiments of the present invention will be explained inmore detail hereinafter.

FIG. 1 shows a thermal insulating cabinet with a thermal insulatingfoamed material of the present invention. Regarding the thermalinsulating cabinet 1, the space part formed by an inner liner 2 made ofan ABS resin and an outer shell 3 made of iron is filled with thethermal insulating foamed material 4 comprising a foamed urethane resincomposition of the present invention.

This thermal insulating foamed material 4 is produced as follows. Thatis, a foamed polyurethane resin composition having the closed cellswhich contain at least carbon dioxide, is formed by injecting a rawmaterial mixture containing polyisocyanate, polyol, a reactive blowingagent which evolves carbon dioxide by reacting with the polyisocyanate,a foam stabilizer, a urethane reaction catalyst, the above-mentionedepoxides and a carbon dioxide reaction catalyst into a space part formedby an inner liner 2 and an outer shell 3, followed by blowing. Then,carbon dioxide in the closed cells is allowed to react with the epoxidesin the presence of carbon dioxide fixation catalyst, thereby to fix thecarbon dioxide as carbonate compounds.

In the present invention, since at least two members of epoxidecompounds of an epoxide compound having high reactivity with carbondioxide and an epoxide compound having low reactivity with carbondioxide are used as epoxides, cyclic carbonate compounds as products ofreactions between carbon dioxide and epoxides comprise at least twomembers of a reaction product of an epoxide compound having highreactivity with carbon dioxide and carbon dioxide and a reaction productof an epoxide compound having low reactivity with carbon dioxide andcarbon dioxide.

These reactions between epoxides and carbon dioxide will be explained inmore detail. First, carbon dioxide, which rapidly evolves at the time offormation of a foamed material and exists in the closed cells of thefoamed material, is fixed by a rapid addition reaction with the epoxidecompound having high reactivity with carbon dioxide in the presence ofthe carbon dioxide fixation catalyst, thereby to reduce the partialpressure of carbon dioxide in the closed cells. Since a volatile blowingagent having an excellent thermal insulating property is normally usedin combination with a reactive blowing agents as the blowing agent, aratio of vapor of this volatile blowing agent in the closed cellsincreases as carbon dioxide is reduced and improves the thermalinsulating property. The fixation of carbon dioxide evolving graduallyfrom the resin composition with a time lapse proceeds due to the epoxycompound having low reactivity with carbon dioxide. That is, one ofconventional problems is solved by allotting each role of carbon dioxidefixation to a plurality of epoxide compounds having different reactivitywith carbon dioxide.

The addition reactions for fixing carbon dioxide using these epoxidecompounds are reactions wherein carbon dioxide and epoxides form cycliccarbonates, as shown in the following formula (1). These reactionseasily proceed at normal temperature under normal pressure in thepresence of the carbon dioxide fixation catalyst. ##STR1##

In the formula (1), R¹, R², R³ and R⁴ represent a hydrogen atom or asubstituent. Although epoxides are represented by a 3-membered ringether, the same reaction occurs in the case of 4-membered or larger ringether.

Carbon dioxide, which exists in the closed cells of the thermalinsulating foamed material, evolves during the production of the foamedurethane resin composition. Carbon dioxide evolves as a result of thecarbodiimide reaction of polyisocyanate as the raw material or evolvesas a result of the reaction between the reactive blowing agent such aswater contained in the polyol composition and polyisocyanate, and playsa role in forming the closed cells by blowing.

Materials used for producing a normal foamed urethane resin can beapplied to polyol and polyisocyanate used in the production method ofthe present invention. A polyol composition is normally prepared byadding a blowing agent, a foam stabilizer, a urethane reaction catalystand the like to polyol. Normally used materials can be applied for thefoam stabilizer and urethane reaction catalyst. Since the carbon dioxidefixation catalyst itself sometimes serves as the urethane reactioncatalyst, it is necessary to appropriately adjust the amount of theurethane reaction catalyst added. If necessary, a flame retardant issometimes added.

The blowing agent used in the present invention is at least a reactiveblowing agent, and it is preferred to use a volatile blowing agent incombination.

As the volatile blowing agent, a volatile organic liquid is used. Thisblowing agent is vaporized by reaction heat generated by the reactionbetween polyol and polyisocyanate, thereby to form the closed cells inthe resultant polyurethane composition. In order to form the closedcells and to make a diameter of the closed cells uniform and fine, theboiling point of the volatile organic liquid is preferably within therange from 20 to 100° C. Specifically, there are hydrocarbon blowingagent such as cyclopentane, n-pentane and the like;hydrochlorofluorocarbon blowing agent such as HCFC-141b, HCFC-123 andthe like; or hydrofluorocarbon blowing agent such as HFC-356mmf,HFC-245fa and the like. As these volatile blowing agents, those having avapor thermal conductivity which is considerably lower than that ofcarbon dioxide are selected. They can be used alone or in combination.

As the reactive blowing agent, compounds which evolves carbon dioxide bythe reaction between the reactive blowing agent and polyisocyanate, suchas water, hydrogen peroxide, lower carboxylic acid and the like may beused. For example, water reacts with an isocyanate group and evolvescarbon dioxide, thereby to form the closed cells. It is particularlyeffective when blowing of the volatile organic liquid is not sufficient.That is, water added reacts with polyisocyanate and the volatile organicliquid is liable to be vaporized by reaction heat. Carbon dioxideevolving as a result of the reaction between water and polyisocyanateassists blowing. Even if the reactive blowing agent is not used, carbondioxide evolves by the carbodiimide reaction which occurs between theisocyanate groups.

Regarding the amount of epoxides added for fixing carbon dioxide, it ispreferred to have an epoxy group in the amount of 1 to 6 mol per mol ofa stoichiometric amount of carbon dioxide evolving by the reactionbetween the reactive blowing agent and polyisocyanate. That is, when theamount is less than 1 mol, it becomes impossible to retain the epoxygroup enough to fix carbon dioxide remaining inside the closed cells ofthe formed thermal insulating foamed material under the conditions atwhich the side reaction between the epoxide compound and polyisocyanateoccurs. Therefore, an effect enough to improve the thermal insulatingproperty can not be obtained. Furthermore, it also becomes impossible toremove carbon dioxide which evolves with a time lapse. When the amountexceeds 6 mol, the amount of the product of the side reaction betweenthe epoxide compound and polyisocyanate increases too much and,therefore, the thermal conductivity of the resin part of the foamedmaterial is liable to increase. Even if the side reaction product can besufficiently inhibited, the amount of the residual liquid epoxy resinbecomes too large and, therefore, productivity is drastically loweredsometimes by delayed development of a mechanical strength of thepolyurethane foamed material or an extension of time up to the time ofmold releasing.

It is possible to use epoxides and the carbon dioxide by mixing themwith the polyol composition or polyisocyanate. It is also possible touse a method of preparing epoxides or a carbon dioxide fixation catalystas a third component, in addition to the polyol and polyisocyanate, andmixing them with the polyol composition and polyisocyanate at the timeof blowing.

It is preferred that polyisocyanate used in the present invention has anisocyanate group in the same amount as that of a hydroxyl group in theraw material, and has an isocyanate group which reacts with 0 to 50% ofan epoxy group of epoxides. According to this construction, it becomespossible to rapidly develop the mechanical strength of the thermalinsulating foamed material without leaving the unreacted epoxy group ofthe required amount or more. It is also possible to retain an epoxygroup required for fixing carbon dioxide which exists inside the closedcells after forming the foamed material. When the amount ofpolyisocyanate is an amount at which polyisocyanate reacts with morethan 50% of epoxy groups of epoxides, not only the side reaction isliable to increase but also the remaining amount of the isocyanate groupis liable to increase. Therefore, the amount of carbon dioxide evolvingwith a time lapse increases.

Regarding epoxides used in the production method of the presentinvention, it is preferred that the epoxide compound having highreactivity with carbon dioxide is an epoxide complex in which the carbondioxide fixation catalyst is coordinated to an oxirane ring. Aparticularly preferred effect can be obtained when the amount of theepoxy group of this epoxide complex is from 0.01 to 1.0 mol per mol ofthe epoxy group of the epoxide compound having low reactivity withcarbon dioxide. That is, when using the epoxide complex, carbon dioxidefixation proceeds efficiently and, at the same time, it also becomespossible to efficiently fix carbon dioxide with respect to the epoxidecompound having low reactivity with carbon dioxide, as mentioned above.Furthermore, since this epoxide complex has a comparatively low activitywith polyol or polyisocyanate, the side reaction can be inhibited.Therefore, the amount of the epoxide complex added to the epoxidecompound having low reactivity with carbon dioxide may be made small andit is not necessary to add an excess epoxide complex. The amount of theabove epoxy group within the range from 0.01 to 1.0 is suitable, but isnot limited to this range.

An excellent effect can be obtained when epoxides used in the productionmethod of the present invention contain an epoxide compound having highreactivity with polyisocyanate and an epoxide compound having lowreactivity with polyisocyanate, and the epoxide compound having lowreactivity with carbon dioxide is an epoxide compound having highreactivity with polyisocyanate. In this case, when a ratio of the amountof the epoxy group of the epoxide compound having high reactivity withpolyisocyanate to the amount of the epoxy group of the epoxide compoundhaving low reactivity with polyisocyanate is from 0.5 to 2.0, aparticularly preferred effect can be obtained. That is, when the aboveratio is less than 0.5, almost all of the epoxide compound having highreactivity with polyisocyanate is converted into a urethane resincomposition by the side reaction between the epoxide compound andpolyisocyanate. Therefore, the mechanical strength is rapidly developedbut contribution to the fixation reaction of carbon dioxide becomessmall. When the above ratio exceeds 2.0, the amount of the product ofthe side reaction between the epoxide compound and polyisocyanateincreases too much and, therefore, the resin thermal conductivity of thefoamed material is liable to increase. Even if the side reaction productcan be sufficiently inhibited, the productivity is drastically loweredsometimes by delayed development of a mechanical strength of thepolyurethane foamed material or an extension of time up to the time ofmold releasing.

An excellent effect can also be obtained when epoxides contain anepoxide compound having a boiling point of more than 120° C. and anepoxide compound having low reactivity with polyisocyanate and a boilingpoint of 120° C. or less, and the epoxide compound having low reactivitywith carbon dioxide is an epoxide compound having low reactivity withpolyisocyanate. In this case, it is preferred that a ratio of the amountof the epoxy group of the epoxide compound having a boiling point ofmore than 120° C. to the amount of the epoxy group of the epoxidecompound having a boiling point of 120° C. or less is from 0.2 to 2.0,because of the same reason as above.

As the outer shell and inner liner, which constitute the thermalinsulating cabinet of the present invention, those which are normallyused for a refrigerator, freezer and the like can be used. As the innerliner material, those capable of preventing air from invading andpreviously subjected to a treatment for imparting gas barrier propertiesare preferred.

The carbon dioxide fixation catalyst and epoxides used in the presentinvention will be explained in more detail hereinafter.

(1) Carbon dioxide fixation catalyst

The carbon dioxide fixation catalyst of the present invention iscomposed of a nucleophile and/or an electrophile. Specifically, as thenucleophile, halogen ion, alkoxy ion, phenoxy ion, perchlorate ion,cyanide ion, acetate ion, para-toluenesulfonic ion and the like may beused. Among them, halogen ion is effective. The effect is particularlyremarkable when the halogen ion is an onium salt or a pair ion of analkali halide.

As the onium salt having the halogen ion as the pair ion, ammonium salt,phosphonium salt, sulfonium salt and the like may be used. Particularly,halogenated tetraalkylammonium salt, halogenated tetraalkylphosphoniumsalt and the like are suitable. In the case of an onium salt having anyalkyl chain, the same effect is obtained. As halogen which becomes thepair ion, chlorine, bromine and iodine are preferred. It is particularlyeffective when using bromine or iodine.

For example, tetramethylammonium halide, tetraethylammonium halide,tetrabutylammonium halide, trimethylbutylammonium halide,benzyltrimethylammonium halide, tetrabutylphosphonium halide,triphenylmethylphosphonium halide, tetraphenylphosphonium halide and thelike can be used.

On the other hand, any alkyl halide can be used as the alkali halide.

As the electrophile, Lewis acid metal halide, organotin halide,organotin fatty acid ester, metal dialkyldithiocarbamate, acetylacetonemetal salt, mercaptopyridine N-oxide metal salt and the like areeffective. As the Lewis acid metal halide, zinc halide aluminum halide,titanium halide, chrome halide, molybdenum halide, tungsten halide, ironhalide, cobalt halide, nickel halide and the like are used.Particularly, zinc halide is preferred. As the organotin halide,trimethyltin halide, tributyltin halide, triphenyltin halide and thelike are used. As the organotin fatty acid ester, dibutyltin dilaurate,dibutyltin diacetate, tributyltin acetate and the like can be used.Examples of the metal dialkyldithiocarbamate include zincdialkyldithiocarbamate, nickel dialkyldithiocarbamate, irondialkyldithiocarbamate, copper dialkyldithiocarbamate and the like.Examples of the acetylacetone metal salt include acetylacetone cobaltsalt, acetylacetone copper salt, acetylacetone zinc salt and the like.As the mercaptopyridine N-oxide metal salt, mercaptopyridine N-oxidezinc salt and the like can be used.

(2) Epoxides

Epoxides used in the present invention are composed of at least twomembers of epoxide compounds, and an excellent effect can be obtainedwhen using any of the following three combinations.

(a) First, in the first combination, an epoxide complex wherein a carbondioxide fixation catalyst coordinated to an oxirane ring is used as anepoxide compound having high reactivity with carbon dioxide.

Hereinafter, utilization of the epoxide complex will be explained.

This epoxide complex is an epoxide complex in which the epoxide compoundis combined with the carbon dioxide fixation catalyst.

Carbon to which the nucleophile is coordinated is β-carbon causing alittle steric hindrance to terminal-end epoxides. To inner epoxides,coordinated are the carbon which causes lesser steric hindrance and thecarbon combined with a substituent having strong electrophlicity. On theother hand, the electrophile sometimes coordinates to one oxygen of theoxirane ring or coordinates to a plurality of oxygens. Regarding theepoxide complex, the rate of fixing carbon dioxide increases if any oneof the nucleophile and electrophile is increased. When both nucleophileand electrophile are coordinated, the rate of fixing carbon dioxideincreases furthermore.

The reactions wherein the nucleophile, electrophile and both of themreact with epoxides and form a complex are shown in the followingformulae (2), (3) and (4), respectively. The complex shown in the rightside reacts with carbon dioxide and forms a cyclic carbonate. ##STR2##

In the above formulae, R¹, R², R³ and R⁴ represent a hydrogen atom or asubstituent; X⁻ represents a nucleophile; and M represents anelectrophile. Although epoxides are represented by a 3-membered ring inthe above formulae, the same reaction occurs in the case of 4-memberedor larger ring.

As the nucleophile, halogen ion is preferred. It is preferred to containthe halogen ion as an onium salt or an alkali metal halide. It ispreferred that the electrophile is selected from the group consisting ofa zinc compound and a tin compound.

The epoxide complex also includes those wherein the nucleophile isfurther coordinated to the electrophile part of the formula (4).

FIG. 2 is a schematic view showing the construction of the thermalinsulating foamed material made by using the epoxide complex of thepresent invention.

This thermal insulating foamed material 10 is composed of a urethaneresin 11 having closed cells 12. In the urethane resin 11, an epoxidecomplex formed by reacting epoxides 13 with a nucleophile 14 and anelectrophile 15 is dispersed and a carbonate 16 formed by reacting thisepoxide complex with carbon dioxide is further dispersed. In FIG. 2, anexample of using both nucleophile 14 and electrophile 15 is shown, butany one of them may be used as a matter of course.

On the other hand, FIG. 3 shows a construction example of the thermalinsulating foamed material of a conventional technique. In comparisonwith FIG. 2, the nucleophile 14 or electrophile 15 dispersed in theurethane resin 11 does not exist in the vicinity of the epoxides 13. InFIG. 3, therefore, the nucleophile 14 or electrophile 15 must move inthe urethane resin 11 so as to react with the epoxides 13 and thefixation rate of carbon dioxide becomes slow.

Advantages of the use of the epoxide complex wherein the carbon dioxidefixation catalyst is coordinated to an oxirane ring are as follows.Regarding the epoxide complex, the carbon dioxide catalyst iscoordinated to the epoxide compound as a complex and, therefore, theabove catalyst and epoxide are dispersed together in the foamed urethaneresin composition in the state of being closed each other. Accordingly,the fixation rate of carbon dioxide becomes larger than that in the casewherein the above catalyst and epoxide complex are separately dispersedin the foamed urethane resin composition. When the polyurethane foamedmaterial is formed, this epoxide complex rapidly fixes carbon dioxide inthe closed cells, thereby to form a cyclic carbonate. Therefore, thepartial pressure of carbon dioxide in the closed cells is lowered,thereby to improve the thermal insulating property.

Furthermore, the epoxide compound having low reactivity with carbondioxide, added together with the epoxide complex, fixes graduallyevolving carbon dioxide with a time lapse. In this case, since thecyclic carbonate compound produced from the epoxide complex contains thecarbon dioxide fixation catalyst and has a high affinity for the epoxidecompound, the fixation of carbon dioxide satisfactorily proceeds usingthe part of this cyclic carbonate compound as a nucleus.

The epoxide complex can be obtained by adding the epoxide compound andcarbon dioxide fixation catalyst in a solvent thereby to react them witheach other, and extracting or separating the resultant epoxide complexfrom the solvent. When the epoxide compound is liquid, the epoxidecomplex can also be obtained by adding the carbon dioxide fixationcatalyst directly to epoxides without using the solvent.

In the present invention, a method of previously preparing the epoxidecomplex and dispersing it in a polyurethane raw material is preferred,but it is also possible to use a method of dispersing epoxides and thecarbon dioxide fixation catalyst in the polyurethane raw material andforming the epoxide complex in the polyurethane raw material. In thiscase, when the epoxide compound and carbon dioxide fixation catalyst aremerely dispersed in the polyurethane raw material, the concentration ofthe carbon dioxide fixation catalyst in the vicinity of epoxides is lowand it becomes difficult to form the epoxide complex. Therefore, thefixation rate of carbon dioxide becomes low. Thus, it is necessary toincrease the concentration of the carbon dioxide fixation catalyst inthe vicinity of epoxides. Therefore, it is possible to use epoxideshaving an active moiety as the carbon dioxide fixation catalyst in themolecule and to use a polymer wherein the epoxy group and carbon dioxidefixation catalyst are introduced into the side chain.

In the method of the present invention, when the epoxide compoundbecomes a solid or high-viscosity oily substance after forming acomplex, it is preferred to use a low-viscosity epoxide compound whichhas low reactivity for fixing carbon dioxide and forms no complex so asto improve handling properties.

Regarding the amount of epoxides for fixing carbon dioxide, the epoxidecomplex having an epoxy group whose molar amount corresponds to that ofcarbon dioxide which exists in the closed cells may be added to thepolyurethane raw material. The epoxide complex may remain in theresultant thermal insulating foamed material by adding the epoxidecomplex whose molar amount is more than that of evolving carbon dioxide.In that case, since the concentration of the epoxide complex in thethermal insulating foamed material increases, a high carbon dioxidefixation rate can be obtained. Furthermore, since the epoxide complexand epoxide compound having low reactivity with carbon dioxide exist inthe thermal insulating foamed material, carbon dioxide which may evolvewith a time lapse can be fixed. Thereafter, a high thermal insulatingproperty can be maintained for a long period of time.

When using the epoxide complex which is a reaction product between zinchalide and onium halide particularly, the urethane reaction rate by zinchalide as the electrophile can be drastically inhibited in the blowingstep and there is an advantage of good handling. This reason isconsidered as follows. That is, in the above-mentioned epoxide complex,both of the zinc halide and onium halide are strongly coordinated to theepoxide to form an epoxide complex and besides, another onium halide iscoordinated to the zinc moiety of the electrophile to form an epoxidecomplex. Therefore, this epoxide complex has lost an intrinsic urethanereaction activity of the zinc halide. It is considered that the sidereaction between the epoxide complex and polyisocyanate is inhibited bythis effect.

As the epoxide compound constituting the epoxide complex of the presentinvention, any compound having an epoxy group or a glycidyl group can beused. It is also possible to utilize a compound having a double-bondedunsaturated group in the molecule, an oligomer having an epoxy group atboth terminal ends and oxetane (boiling point: 50° C.) or a derivativethereof. The epoxide compound may take any form such as vapor, liquidand solid. The epoxide compound of the present invention can combine thethermal insulating foamed material with the epoxy group when usingepoxides having a plurality of epoxy groups or a plurality of functionalgroups such as hydroxyl group, carboxyl group, amino group and the like.Therefore, the effect of a curing agent on increasing the mechanicalstrength of the thermal insulating foamed material can be obtained. Whena reactive-type flame retardant having an epoxy group (e.g., brominatedphenylglycidyl ether, etc.) is used in combination with the epoxidecompound, flame-retarding of the thermal insulating foamed material canbe performed.

The following advantages can be obtained when using the epoxide compoundhaving a boiling point of 120° C. or less as the epoxide complex.Although the epoxide compound having a boiling point of 120° C. or lessis liable to be evaporated by heat evolving in the process of formingthe foamed material, the epoxide complex is not easily vaporized.Therefore, the state where the carbon dioxide fixation catalyst iscoordinated to the oxirane ring is held in the foamed material formingprocess and fixation of carbon dioxide by the epoxide compoundefficiently proceeds.

Specific examples of the above-mentioned epoxide compound having aboiling point of 120° C. or less for constituting the epoxide complexinclude ethylene oxide (boiling point: 11° C.), propylene oxide (boilingpoint: 34° C.), 1,2-butylene oxide (boiling point: 63° C.), cis2,3-butylene oxide (boiling point: 60° C.), trans 2,3-butylene oxide(boiling point: 54° C.), isobutylene oxide (boiling point: 52° C.),butadiene monoxide (boiling point: 65° C.), epichlorohydrin (boilingpoint: 110° C.), glycidyl methyl ether (110° C.), epoxyhexane (boilingpoint: 118° C.), epoxyhexene (boiling point: 119° C.) and the like.

Specific examples of other epoxide compound include normal epoxidecompounds such as epoxyoctane, epoxydecane, epoxydodecane,epoxyhexadecane, epoxyoctadecane, epoxyoctene, glycidyl butyl ether,glycidyl isopropyl ether, glycidyl acrylate, glycidyl methacrylate,phenyl glycidyl ether, allyl glycidyl ether, epoxypropylbenzene, styreneoxide, N-(2,3-epoxypropyl)phthalimide and the like.

It is preferred that the epoxide compound having high reactivity withcarbon dioxide is an epoxide complex wherein the carbon dioxide fixationcatalyst is coordinated to an alkylene oxide, and the epoxide compoundhaving low reactivity with carbon dioxide is an alkylene oxide. Theconstruction wherein the epoxide compound having high reactivity withcarbon dioxide is an epoxide complex in which the carbon dioxidefixation catalyst is coordinated to an alkylene oxide, and the epoxidecompound having low reactivity with carbon dioxide comprises an alkyleneoxide and a glycidyl ether is preferred.

The epoxide complex wherein the carbon dioxide fixation catalyst iscoordinated to an alkylene oxide is in the solid or oil state and has alow compatibility with the alkylene oxide and, therefore, a dispersedstate is obtained even if they are mixed. Since this epoxide complex hasa low affinity for polyol, the foamed material is formed from thedispersion while this epoxide complex gradually becomes affinitive atthe time of forming the polyurethane foamed material. Therefore, thisepoxide complex becomes the state where the concentration is high at thedispersed part, thereby to fix carbon dioxide more efficiently incomparison with the epoxide complex which becomes the compatibilizedstate. The alkylene oxide has a low compatibility with this epoxidecomplex, but has a good compatibility with a carbonate compound producedby fixing carbon dioxide. Therefore, fixation of carbon dioxidesatisfactorily proceeds using the position where fixation hassufficiently proceeded as a nucleus. Furthermore, glycidyl ethers aresuitable for adjusting the compatibility between the epoxide complexwherein the carbon dioxide fixation catalyst is coordinated to analkylene oxide and the alkylene oxide, and adjusting the fixation rateof carbon dioxide. Examples of the other epoxide compound having thisfunction include glycidyl esters, glycidylamines and the like.

Specific examples of the above-mentioned alkylene oxide include1,2-butylene oxide, cis 2,3-butylene oxide, trans 2,3-butylene oxide,isobutylene oxide, ethylene oxide, propylene oxide, epoxyhexane,epoxyoctane, epoxydecane, epoxydodecane, epoxyhexadecane,epoxyoctadecane and the like. The same effect can be obtained by acompound having an epoxy group and a double-bonded unsaturated group,such as epoxyhexene, epoxyoctene, butadiene monoxide and the like.

The rate of forming a complex by reacting the epoxide compound with thecarbon dioxide fixation catalyst varies depending on the epoxidecompound or carbon dioxide fixation catalyst to be used. Therefore, itis sometimes insufficient to merely mix the epoxide compound with thecarbon dioxide fixation catalyst for a short time in order to form acomplex. When the solubility of the carbon dioxide fixation catalyst inthe epoxide compound is particularly low, the complex formation rate islow and, therefore, it is necessary to sufficiently mix epoxide with thecarbon dioxide fixation catalyst with stirring. For example, when zincchloride is mixed with brominated tetrabutylammonium with stirring toform a complex, the respective carbon dioxide fixation catalysts and theresultant epoxide complex do not easily dissolve in 1,2-butylene oxideand, therefore, a comparatively long stirring is required to form acomplex. This complex is formed in the dispersed state of a whitepowdered solid.

On the other hand, when a complex is formed by mixing phenyl glycidylether, zinc chloride and brominated tetrabutylammonium with stirring,the respective carbon dioxide fixation catalysts easily dissolve inepoxides and, therefore, a complex is formed in a comparatively shorttime. When the nucleophile and electrophile are used as the carbondioxide fixation catalyst, an epoxide complex can be efficiently formedby previously forming a complex salt from the nucleophile andelectrophile and adding the resultant complex salt to epoxides. In thecase of the combination of the above-mentioned 1,2-butylene oxide, zincchloride and brominated tetrabutylammonium, for example, a complex saltis previously made from zinc chloride and brominated tetrabutylammonium,and then the resultant complex salt is added to 1,2-butylene oxide.

(b) Next, the second combination of epoxides is exemplified thatepoxides contain an epoxide compound having high reactivity withpolyisocyanate and an epoxide compound having low reactivity withpolyisocyanate, and the epoxide compound having low reactivity withcarbon dioxide is an epoxide compound having high reactivity withpolyisocyanate.

When using such epoxides, the epoxide compound having high reactivitywith polyisocyanate reacts with polysiocyanate, preferentially andrapidly, in comparison with the epoxide compound having low reactivitywith polyisocyanate, thereby to constitute the resin component.Accordingly, development of the mechanical strength of the foamedmaterial rapidly proceeds and, at the same time, an excellent foamedmaterial having low resin thermal conductivity can be formed withoutincreasing the thermal conductivity of the resin of the polyurethanefoamed material.

On the other hand, the epoxide compound having low reactivity withpolyisocyanate has an activity to fixation of carbon dioxide and fixescarbon dioxide, rapidly and sufficiently, at the time of forming thefoamed material, thereby to reduce a partial pressure of carbon dioxideinside the closed cells. When a volatile blowing agent is contained inthe closed cells, a ratio of vapor of the volatile blowing agentincreases. Therefore, an increase in vapor thermal conductivity causedby carbon dioxide of the thermal insulating foamed material can beimproved. In addition, the epoxy group remaining in the resin component,formed by the reaction of the epoxide compound having high reactivitywith polyisocyanate, has low reactivity with carbon dioxide, but plays arole of slowly fixing carbon dioxide which evolves gradually with a timelapse and prevents the vapor thermal conductivity from increasing.Accordingly, a thermal insulating foamed material having highreliability can be provided.

Explaining a specific construction, the first construction isexemplified that the epoxide compound having high reactivity withpolyisocyanate is a polyglycidyl ether having two or more epoxy groups,and the epoxide compound having low reactivity with polyisocyanate is amonoglycidyl ether having one epoxy group. It is preferred becausepolyglycidyl ethers having two or more epoxy groups is polyfunctionaland a component having a sufficient strength is constituted as theurethane resin component. The epoxy groups remaining without beingconverted into a resin can fix carbon dioxide which evolves with a timelapse.

As the specific epoxide compound, monoglycidyl ethers having one epoxygroup, such as allyl glycidyl ether, butyl glycidyl ether, phenylglycidyl ether or a derivative thereof, are preferred. As polyglycidylethers having two or more epoxy groups, various epoxy resins representedby ethylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether,pentaerythritol polyglycidyl ether or condensates of bisphenol A withepichlorohydrin are preferred. A brominated bisphenol A epoxy resin canalso be applied.

The second construction is exemplified that the epoxide compound havinghigh reactivity with polyisocyanate is a polyglycidyl ether having atleast one hydroxyl group, and the epoxide compound having low reactivitywith polyisocyanate is a glycidyl ether having no hydroxyl group.Regarding glycidyl ethers having a hydroxyl group, the hydroxyl grouphas the same reaction activity as that of polyol and selectively reactswith polyisocyanate. The epoxy group also reacts with polyisocyanate,thereby to constitute the resin component. Regarding those wherein onlya hydroxyl group has reacted, an epoxy group remains and the epoxy groupcan fix carbon dioxide evolving with a time lapse.

Specific examples of the epoxide compound include glycidyl ether havingat least one hydroxyl group, such as glycidol, glycerol polyglycidylether and the like. Examples of the glycidyl ether having no hydroxylgroup include monoglycidyl ethers such as phenyl glycidyl ether and thelike; and polyglycidyl ethers such as ethylene glycol diglycidyl etherand the like. A polyfunctional polymer epoxy compound is preferred.

Third, the construction wherein the epoxide compound having highreactivity with polyisocyanate is a polyglycidylamine, and the epoxidecompound having low reactivity with polyisocyanate is a glycidyl etheris preferred. Since polyglycidyl ethers per se have a catalytic activityfor urethane reaction, the reaction activity with polyisocyanate is thesame as or more than that of polyol. Therefore, they selectively reactwith polyisocyanate, thereby to constitute the resin component having asufficient strength.

Specific examples of the epoxide compound include glycidyl aminesrepresented by polyglycidylamine type epoxy resin such as grade 604(manufactured by YUKA SHELL EPOXY Co., Ltd.), grade ELM-120(manufactured by SUMITOMO Chemical Industries Co., Ltd.) and the like.Examples of glycidyl ethers include monoglycidyl ethers such as phenylglycidyl ether and the like; and polyglycidyl ethers such as ethyleneglycol diglycidyl ether and the like. A polyfunctional polymer epoxycompound is preferred.

The above-mentioned specific epoxide compounds are typical examples, andare not limited to these combinations.

(c) The third combination of epoxides is exemplified that epoxidescontain an epoxide compound having a boiling point of more than 120° C.and an epoxide compound having low reactivity with polyisocyanate and aboiling point of 120° C. or less, and the epoxide compound having lowreactivity with carbon dioxide is an epoxide compound having lowreactivity with polyisocyanate.

When using the epoxides, the epoxide compound having a boiling point of120° C. or less is vaporized by reaction heat generated in the foamedresin composition at the time of blowing and, therefore, the reactionbetween epoxide and polyisocyanate scarcely proceeds. After forming thepolyurethane foamed material having a sufficient mechanical strength,the epoxide fixes carbon dioxide inside the closed cells, thereby toimprove the thermal conductivity. Furthermore, this epoxide compoundalso plays a role of fixing carbon dioxide that evolves with a timelapse, and a thermal insulating foamed material having high reliabilitycan be obtained.

On the other hand, the epoxide compound having a boiling point of morethan 120° C. contributes to rapid fixation of carbon dioxide in theclosed cells at the time of blowing. Since this epoxide compoundsimultaneously performs fixation of carbon dioxide and side reactionwith the polyisocyanate, those which cause little deterioration of thethermal conductivity of the resin are selected.

It is preferred that the above-mentioned epoxide compound having aboiling point of more than 120° C. is a glycidyl ether, a glycidyl esteror a glycidylamine, and the epoxide compound having a boiling point of120° C. or less is an alkylene oxide. The above-mentioned generalepoxide compounds are used as glycidyl ethers and glycidylamines. Thegeneral epoxide compound can also be applied to glycidyl esters.Examples thereof include glycidyl methacrylate, glycidyl benzoate,diglycidyl phthalate and a derivative thereof.

Specific examples of the present invention will be explained in detailhereinafter.

EXAMPLE 1

A white solid epoxide complex (average epoxy equivalent: 630) wasprepared from 1,2-butylene oxide, zinc chloride and tetraethylammoniumbromide. 32.3 parts by weight (hereinafter "parts by weight" areabbreviated to "parts") of this epoxide complex was dispersed in 7.1parts of 1,2-epoxyoctane (epoxy equivalent: 128), thereby to prepare amixed solution of the epoxide complex and epoxide compound. A ratio(hereinafter abbreviated to an "epoxide complex mixing ratio") of themolar amount of the epoxy group of the epoxide complex to that of theepoxy group of the epoxide compound in this mixed solution is about0.93.

A polyol composition was prepared by mixing 35.9 parts of an epoxidecomprising this mixed solution for fixing carbon dioxide, 100 parts ofan aromatic amine polyether polyol (hydroxyl group value: 500 mg KOH/g),15 parts of cyclopentane, 1 part of water, 3 parts of a foam stabilizerand 3 parts of a urethane reaction catalyst.

A mixing/blowing step was performed using this polyol composition and133 parts of polyisocyanate, thereby to obtain a polyurethane foamedmaterial.

When the urethane reaction catalyst was not added, the resultant polyolcomposition hardly accelerated a urethane reaction rate. That is, acarbon dioxide fixation catalyst did not accelerate the urethanereaction by forming an epoxide complex.

EXAMPLE 2

8.0 parts of 1,2-butylene oxide (epoxy equivalent: 72), 1.2 parts ofzinc chloride and 5.7 parts of tetrabutylammonium bromide were mixed,followed by stirring for 3 days. In such way, epoxides (epoxide complexmixing ratio: about 0.09) wherein the epoxide complex and epoxidecompound are mixed were prepared. This epoxide complex was formed as aseparated white solid substance in an epoxide solution.

On the other hand, a mixed solution wherein 100 parts of an aromaticamine polyether polyol (hydroxyl group value: 500 mg KOH/g), 15 parts ofcyclopentane, 1 part of water, 3 parts of a foam stabilizer and 3 partsof a urethane reaction catalyst are mixed was prepared. A polyolcomposition was prepared by adding 15 parts of epoxides prepared aboveto this solution.

A mixing/blowing step was performed using this polyol composition and133 parts of polyisocyanate, thereby to obtain a polyurethane foamedmaterial.

EXAMPLE 3

16.7 parts of 1,2-epoxyhexane (epoxy equivalent: 100), 0.6 parts of zincchloride and 5.7 parts of tetrabutylammonium bromide were mixed,followed by stirring for 3 days, thereby to prepare an epoxide mixedsolution (epoxide complex mixing ratio: about 0.03) wherein the epoxidecomplex and epoxide compound are mixed. This epoxide complex was formedas a separated yellow oily substance in an epoxide solution.

On the other hand, a mixed solution wherein 100 parts of an aromaticamine polyether polyol (hydroxyl group value: 500 mg KOH/g), 15 parts ofcyclopentane, 1 part of water, 3 parts of a foam stabilizer and 3 partsof a urethane reaction catalyst are mixed was prepared. A polyolcomposition was prepared by adding 30.6 parts of epoxides solutionprepared above to this solution.

A mixing/blowing step was performed using this polyol composition and133 parts of polyisocyanate, thereby to obtain a polyurethane foamedmaterial.

EXAMPLE 4

8.0 parts of 1,2-butylene oxide, 1.2 parts of zinc chloride and 5.7parts of tetrabutylammonium bromide were mixed, followed by stirring for3 days, thereby to prepare a mixture of the epoxide complex and epoxidecompound. This epoxide complex was formed as a separated white solidsubstance in an epoxide solution. 5 parts of neopentyl glycol diglycidylether (average epoxide equivalent: 108) was further mixed with thismixed solution with stirring, thereby to obtain epoxides (epoxidecomplex mixing ratio: about 0.06). Almost all the epoxide complex wasseparated as a white solid, while the remainder dissolved in the epoxidecompound solution, thereby to form a pale yellow mixed solution. At thistime, the compatibility of the solid content with the mixed solution ofthe epoxide compound increased and, therefore, the dispersed state wasimproved.

On the other hand, a mixed solution wherein 100 parts of an aromaticamine polyether polyol (hydroxyl group value: 500 mg KOH/g), 15 parts ofcyclopentane, 1 part of water, 3 parts of a foam stabilizer and 3 partsof a urethane reaction catalyst are mixed was prepared.

A mixing/blowing step was performed using this polyol composition, 133parts of polyisocyanate and 19.9 parts of epoxides for fixing carbondioxide prepared above, thereby to obtain a polyurethane foamedmaterial.

Comparative Example 1

In the same manner as in Example 2 except for reducing the stirring timein the case of mixing 1,2-butylene oxide, zinc chloride andtertabutylammonium bromide to 5 minutes in Example 2, a polyolcomposition was prepared. A mixing/blowing step was performed using thispolyol composition and 133 parts of polyisocyanate. As a result, theurethane reaction rate was considerably high and a good polyurethanefoamed material could not be obtained.

Therefore, a blowing was performed without adding the urethane reactioncatalyst, thereby to obtain a polyurethane foamed material.

Comparative Example 2

In the same manner as in Example 3 except for reducing the stirring timein the case of mixing 1,2-epoxyhexane, zinc chloride andtertabutylammonium bromide to 5 minutes in Example 3, a polyurethanefoamed material was obtained. In the same manner as in ComparativeExample 1, the urethane reaction rate was considerably high and a goodpolyurethane foamed material could not be obtained. Therefore, apolyurethane foamed material was made by adding no urethane reactioncatalyst.

With respect to the polyurethane foamed materials obtained in Examples 1to 4 and those obtained in Comparative Examples 1 and 2, the amount ofcarbon dioxide in the closed cells per 1000 cc of the foamed materialone day after blowing was determined by gas chromatography. Furthermore,the thermal conductivity of the foamed material one day after blowingwas measured. The respective results of measurement are shown inTable 1. In the examples of the present invention, the amount of carbondioxide in the closed cells was smaller than that of the comparativeexamples and good results of the thermal insulating property wereobtained. In the examples, the fixation of carbon dioxide proceeds witha time lapse and a thermal insulating foamed material with an improvedthermal insulating property could be obtained. In the comparativeexamples, the epoxide complex was hardly formed and the urethanereaction catalyst could not be added and, therefore, a sufficientmechanical strength of the foamed material was not obtained andshrinkage occurred with a time lapse.

                  TABLE 1                                                         ______________________________________                                                 Amount of carbon dioxide                                                                    Thermal                                                         per 1000 cc of foamed                                                                       conductivity                                                    material (cc) (W/mK)                                                 ______________________________________                                        Example 1  78              0.0206                                             Example 2  110             0.0209                                             Example 3  121             0.0211                                             Example 4  60              0.0204                                             Comparative                                                                              153             0.0216                                             Example 1                                                                     Comparative                                                                              190             0.0221                                             Example 2                                                                     ______________________________________                                    

EXAMPLE 5

A polyol composition as a solution A was prepared from 100 parts byweight of an aromatic amine polyether polyol having a hydroxyl groupvalue of 460 (mg KOH/g), 2.0 parts of KAOLIZER No.1 manufactured by KaoCorporation as the urethane reaction catalyst, 1.5 parts of a siliconesurfactant F-335 manufactured by Shin-Etsu Chemical Co., Ltd. as thefoam stabilizer, 1.0 part of water as the reactive blowing agent andcyclopentane as the volatile blowing agent. The formulation ratio ofcyclopentane was adjusted so that the free blow density of the resultantthermal insulating foamed material becomes 25-27 kg/m³. As epoxides forfixing carbon dioxide, phenylglycidyl ether (epoxy equivalent: 150) asmonoglycidyl ethers was mixed with a bisphenol A type epoxy resin grade828 (average epoxy equivalent: 190) manufactured by YUKA SHELL EPOXYCo., Ltd. as polyglycidyl ethers, followed by mixing withtetrabutylammonium bromide as the carbon dioxide fixation catalyst. Theresultant is referred to as a "solution B". The mixing ratio of therespective components in the solution B is shown in Table 2 (it is basedon 100 parts by weight of the above-mentioned polyether polyol. It isthe same in the following examples). A polyol composition was preparedby mixing this solution B with the above-mentioned solution A. On theother hand, CLUDE MDI having an amine equivalent of 135 was used aspolyisocyanate.

The total amount of epoxides corresponds to the amount containing theepoxy group of about 4 mol per mol (stoichiometric amount) of carbondioxide generated by the reaction between 1.0 part of water as thereactive blowing agent and polyisocyanate.

The ratio (Ep/Em, hereinafter referred to as an "epoxy ratio") of themolar amount (Ep) of the epoxy group of polyglycidyl ethers to the molaramount (Em) of the epoxy group of monoglycidyl ethers is also shown inTable 2.

The polyol composition thus prepared was mixed with polyisocyanate in aratio that an NCO group is formulated in an amount of 1.05 equivalentsper hydroxyl group of the polyol composition, and then the resultant rawmaterial mixture was injected into the space part formed by an innerliner and an outer shell and blown. In such way, a thermal insulatingcabinet whose space part is filled with the polyurethane foamed materialwas obtained. The formulation ratio of polyisocyanate corresponds to theamount wherein the excess NCO groups corresponding to about 25% of theepoxy groups of epoxides are added to the NCO groups of the sameequivalent as that of the hydroxyl groups in the raw material.

With respect to the thermal insulating cabinet thus obtained, thethermal insulating foamed material was collected after a predeterminedaging time has passed. Then, the thermal conductivity of the thermalinsulating foamed material and gas composition in the same foamedmaterial were determined. In order to examine the development state ofthe mechanical strength of the thermal insulating foamed material, thethermal insulating cabinet was removed from the mold after 8 minuteshave passed after blowing. Then, the amount of expansion of the sidepart of the thermal insulating cabinet formed after removal from themold was measured. These results are shown in Table 2. In Table 2, "CP"in the column of the gas composition indicates cyclopentane (it is alsothe same in the following Tables).

Comparative Example 3

With respect to the case where polyglycidyl ethers are removed from theraw material mixture of Example 5 (Comparative Example 3-1) and the casewhere monoglycidyl ethers are removed from the raw material mixture ofExample 5 (Comparative Example 3-2), a thermal insulating foamedmaterial was obtained in the same manner as stated above. With respectto the case where the formulation ratio of polyisocyanate was adjustedso that the amount of the NCO group becomes 0.95 equivalents perhydroxyl group of the polyol composition (Comparative Example 3-3) andthe case where the amount of the NCO group becomes 1.15 equivalents perhydroxyl group of the polyol composition (Comparative Example 3-4) inExample 5-2, a thermal insulating foamed material was obtained in thesame manner as stated above. In Comparative Example 3-4, the excess NCOgroups which are enough to be able to react with 50% or more of theepoxy groups in epoxides are formulated. The results of thesecomparative examples are also shown in Table 2.

                                      TABLE 2                                     __________________________________________________________________________                       Example     Comparative Example                                               5-1 5-2 5-3 3-1 3-2 3-3 3-4                                __________________________________________________________________________    Mixing                                                                             Monoglycidyl ethers                                                                         21.7                                                                              17.4                                                                              13.0                                                                              34.8    17.4                                                                              17.4                               ratio of                                                                           Polyglycidal ethers                                                                         13.8                                                                              18.3                                                                              22.9    36.7                                                                              18.3                                                                              18.3                               solution                                                                           Carbon dioxide fixation                                                                     2.0 2.0 2.0 2.0 2.0 2.0 2.0                                B    catalyst                                                                 Epoxy ratio (Ep/Em)                                                                              0.50                                                                              0.83                                                                              1.39                                                                              0   --  0.83                                                                              0.83                               Equivalent of NCO per hydroxyl group                                                             1.05                                                                              1.05                                                                              1.05                                                                              1.05                                                                              1.05                                                                              0.95                                                                              1.15                               Evaluation                                                                         one                                                                              Thermal conductivity                                                                     0.0172                                                                            0.0170                                                                            0.0170                                                                            0.0175                                                                            0.0180                                                                            0.0170                                                                            0.0180                             results                                                                            day                                                                              (W/mK)                                                                after   Gas    CO.sub.2                                                                          5   5   5   5   25  5   25                                 aging   composition                                                                          CP  95  95  95  95  75  95  75                                         (%)                                                                   one     Thermal conductivity                                                                     0.0171                                                                            0.0170                                                                            0.0169                                                                            0.0175                                                                            0.0170                                                                            0.0170                                                                            0.0170                             week    (W/mK)                                                                after   Gas    CO.sub.2                                                                          5   5   5   5   5   5   5                                  aging   composition                                                                          CP  95  95  95  95  95  95  95                                         (%)                                                                   Expansion amount of thermal                                                                      <3 mm                                                                             <3 mm                                                                             <3 mm                                                                             6-8 mm                                                                            <3 mm                                                                             5-7 mm                                                                            <3 mm                              insulating cabinet                                                            __________________________________________________________________________

In Example 5, monoglycidyl ethers and polyglycidyl ethers are used asepoxides. The resultant thermal insulating foamed material includesproducts of side reactions such as polymerization of epoxides andpolyisocyanate, polymerization of epoxides and polyol and polymerizationof epoxides. However, as is apparent from a comparison betweencharacteristics of foamed materials shown in Table 2, the thermalconductivity of the resin of the polyurethane foamed material is notincreased. Carbon dioxide which is generated by the reaction betweenwater and polyisocyanate and remains inside the closed cells is rapidlyfixed, and the ratio of cyclopentane as the volatile blowing agent isincreased. In such way, a thermal insulating foamed material having anexcellent thermal insulating property is obtained by using monoglycidylethers and polyglycidyl ethers as epoxides.

Comparative Example 3-1 is an example using only monoglycidyl ethers asthe epoxide compound for fixing carbon dioxide. According to thisexample, a capability of sufficiently fixing carbon dioxide whichevolves in the blowing step is obtained but the thermal conductivity ofthe thermal insulating foamed material is larger than that of theexamples. This reason is considered as follows. That is, monoglycidylethers reacted with polyisocyanate in not a little degree in the formingprocess of the thermal insulating foamed material and the thermalconductivity of the resin of the resultant thermal insulating foamedmaterial was decreased due to the reaction product and, therefore, thethermal conductivity of the thermal insulating foamed material could notbe sufficiently improved after fixing carbon dioxide. The thermalinsulating foamed material takes a lot of time to develop the mechanicalstrength and the expansion amount of the thermal insulating cabinetafter removal from the mold is large, which results in remarkabledeteriorations of appearance and quality of the thermal insulatingcabinet.

Comparative Example 3-2 is an example using only polyglycidyl ethers asthe epoxide compound for fixing carbon dioxide. The thermal conductivityof the resultant thermal insulating foamed material was finally improvedto the same property as that of Example 5. However, an aging time ofabout one week is required and the productivity is drastically poor.This reason is considered as follows. That is, the fixation rate ofcarbon dioxide is low and the decrease amount of carbon dioxide islittle at the stage of an aging time of about one day.

Comparative Example 3-3 is an example wherein the formulation ratio ofpolyisocyanate was adjusted so that the amount of the NCO group becomes0.95 equivalents per hydroxyl group of the polyol composition. Accordingto this example, the thermal insulating foamed material takes a lot oftime to develop the mechanical strength and the expansion amount of thethermal insulating cabinet after removal from the mold is large, whichresults in remarkable deteriorations of appearance and quality of thethermal insulating cabinet.

Comparative Example 3-4 is an example wherein the excess NCO groupswhich are enough to be able to react with 50% or more of the epoxygroups in epoxides are formulated. In this case, the unreacted epoxygroup can not remain sufficiently and an aging time of about one week isrequired to finally improve the thermal conductivity to the sameproperty as that of Example 5, and the productivity is drastically poor.

EXAMPLE 6

A mixed solution prepared in the same manner as in Example 5 was used asthe solution A of the polyol composition.

As epoxides, glycidol of glycidyl ethers having a hydroxyl group (epoxyequivalent: 74) was mixed with a bisphenol A type epoxy resin grade 828(average epoxy equivalent: 190) manufactured by YUKA SHELL EPOXY Co.,Ltd as glycidyl ethers having no hydroxyl group. To this mixture wasadded tetrabutylammonium bromide as the carbon dioxide fixationcatalyst, thereby to obtain a solution C. The mixing ratio of therespective components of the solution C is shown in Table 3.

The total amount of epoxides corresponds to the amount containing theepoxy group of about 4 mol per mol (stoichiometric amount) of carbondioxide generated by the reaction between 1.0 part of water of thereactive blowing agent and polyisocyanate.

The ratio (Eh/El) of the molar amount (Eh) of the epoxy group ofpolyglycidyl ethers having a hydroxyl group to the molar amount (El) ofthe epoxy group of monoglycidyl ethers having no hydroxyl group, thatis, the ratio of the molar amount of the epoxy group of glycidyl ethershaving high reactivity with isocyanate to the molar amount of the epoxygroup of glycidyl ethers having low reactivity with isocyanate is alsoshown in Table 3.

The mixed solution A of the polyol composition, mixed solution C and thesame polyisocyanate as that of Example 5 were injected into the spacepart formed between the inner liner and the outer shell and blown, usinga high-pressure blowing machine. The formulation ratio of polyisocyanatewas adjusted so that the amount of the NCO group becomes 1.05equivalents per hydroxyl group in the mixed solution A and mixedsolution C. This amount corresponds to the amount wherein the NCO groupsof the same equivalent as that of the hydroxyl group in the raw materialand excess NCO groups corresponding to about 25% of epoxy groups of theepoxide compound are added.

With respect to the thermal insulating cabinet thus obtained, thethermal insulating foamed material was collected after a predeterminedaging time has passed in the same manner as in Example 5. Then, thethermal conductivity of the thermal insulating foamed material and gascomposition in the same foamed material were determined. In the samemanner as in Example 5, the amount of expansion of the side part of thethermal insulating cabinet formed after removal from the mold wasmeasured. These results are shown in Table 3.

Comparative Example 4

With respect to the case where glycidyl ethers having a hydroxyl groupare removed from the raw material mixture of Example 6 (ComparativeExample 4-1) and the case where glycidyl ethers having no hydroxyl groupare removed from the raw material mixture of Example 6 (ComparativeExample 4-2), a thermal insulating foamed material was obtained in thesame manner as stated above. With respect to the case where theformulation ratio of polyisocyanate was adjusted so that the amount ofthe NCO group becomes 0.95 equivalents per hydroxyl group in the polyolcomposition and epoxides (Comparative Example 4-3) and the case wherethe amount of the NCO group becomes 1.15 equivalents per hydroxyl groupof the polyol composition and epoxides (Comparative Example 4-4) inExample 6-2, a thermal insulating foamed material was obtained in thesame manner as stated above. In Comparative Example 4-4, the excess NCOgroups which are enough to be able to react with 50% or more of theepoxy groups in epoxides are formulated. The results of thesecomparative examples are also shown in Table 3.

As is apparent from a comparison shown in Table 3, it becomes possibleto rapidly fix carbon dioxide remaining inside the closed cells and toincrease the ratio of cyclopentane as the volatile blowing agent withoutincreasing the resin thermal conductivity of the polyurethane foamedmaterial by using a mixture of glycidyl ethers having a hydroxyl groupand glycidyl ethers having no hydroxyl group as epoxides, thereby toobtain a thermal insulating foamed material having an excellent thermalinsulating property. It is also possible to rapidly develop themechanical strength of the thermal insulating foamed material, therebyto improve the productivity.

In Comparative Example 4-1, it was possible to finally improve to thesame property as that of Example 6 in the same manner as in ComparativeExample 3-1, but the productivity was drastically deteriorated.

In Comparative Example 4-2, the productivity was drasticallydeteriorated in the same manner as in

Comparative Example 3-2.

In Comparative Example 4-3, the appearance and quality of the thermalinsulating cabinet were drastically deteriorated in the same manner asin Comparative Example 3-3.

In Comparative Example 4-4, the productivity was drasticallydeteriorated in the same manner as in Comparative Example 3-4.

                                      TABLE 3                                     __________________________________________________________________________                       Example     Comparative Example                                               6-1 6-2 6-3 4-1 4-2 4-3 4-4                                __________________________________________________________________________    Mixing                                                                             Glycidyl ethers having no                                                                   22.9                                                                              18.3                                                                              13.8                                                                              36.7    18.3                                                                              18.3                               ratio of                                                                           hydroxyl group                                                           solution                                                                           Glycidyl ethers having                                                                      6.2 8.2 10.3    16.4                                                                              8.2 8.2                                C    hydroxyl group                                                                Carbon dioxide fixation                                                                     2.0 2.0 2.0 2.0 2.0 2.0 2.0                                     catalyst                                                                 Epoxy ratio (Eh/El)                                                                              0.69                                                                              1.16                                                                              1.90                                                                              0   --  1.16                                                                              1.16                               Equivalent of NCO per hydroxyl group                                                             1.05                                                                              1.05                                                                              1.05                                                                              1.05                                                                              1.05                                                                              0.95                                                                              1.15                               Evaluation                                                                         one                                                                              Thermal conductivity                                                                     0.0171                                                                            0.0169                                                                            0.0169                                                                            0.0180                                                                            0.0190                                                                            0.0170                                                                            0.0180                             results                                                                            day                                                                              (W/mK)                                                                after   Gas    CO.sub.2                                                                          5   5   5   25  50  5   25                                 aging   composition                                                                          CP  95  95  95  75  50  95  75                                         (%)                                                                   one     Thermal conductivity                                                                     0.0171                                                                            0.0169                                                                            0.0169                                                                            0.0170                                                                            0.0180                                                                            0.0170                                                                            0.0170                             week    (W/mK)                                                                after   Gas    CO.sub.2                                                                          5   5   5   5   25  5   5                                  aging   composition                                                                          CP  95  95  95  95  75  95  95                                         (%)                                                                   Expansion amount of thermal                                                                      <3 mm                                                                             <3 mm                                                                             <3 mm                                                                             <3 mm                                                                             <3 mm                                                                             5-7 mm                                                                            <3 mm                              insulating cabinet                                                            __________________________________________________________________________

EXAMPLE 7

A mixed solution prepared in the same manner as in Example 5 was used asthe solution A of the polyol composition.

As epoxides, a bisphenol A type epoxy resin grade 828 (average epoxyequivalent: 190) manufactured by YUKA SHELL EPOXY Co., Ltd as glycidylethers was mixed with a polyglycidyl amine type epoxy resin grade 604(average epoxy equivalent: 120) manufactured by YUKA SHELL EPOXY Co.,Ltd. as glycidylamines. To this mixture added was tetrabutylammoniumbromide as the carbon dioxide fixation catalyst. This mixed solution isreferred to as a "solution D". The mixing ratio of the respectivecomponents of the solution D is shown in Table 4. A polyol compositionwas prepared by mixing the solution D with the above-mentioned solutionA. CLUDE MDI having an amine equivalent was used as polyisocyanate.

The total amount of the epoxide compounds corresponds to the amountcontaining the epoxy group of about 4 mol per mol (stoichiometricamount) of carbon dioxide generated by the reaction between 1.0 part ofwater of the reactive blowing agent and polyisocyanate.

The ratio (Ea/Ee) of the molar amount (Ea) of the epoxy group ofglycidylamines to the molar amount (Ee) of the epoxy group of glycidylethers is shown as the epoxy ratio in Table 4.

The above-mentioned polyol composition was mixed with polyisocyanate ina ratio that the NCO groups are formulated in an amount of 1.05equivalents per hydroxyl group of the polyol composition, and then thisraw material mixture was injected into the space part formed between theinner liner and the outer shell and blown, using a high-pressure blowingmachine. The formulation ratio corresponds to the amount wherein the NCOgroups of the same equivalent as that of the hydroxyl groups in the rawmaterial and excess NCO groups corresponding to about 25% of epoxidegroups of the epoxide compounds are added.

With respect to the thermal insulating cabinet thus obtained, thethermal insulating foamed material was collected after a predeterminedaging time has passed according to the same manner as in Example 5.Then, the thermal conductivity of the thermal insulating foamed materialand gas composition in the same foamed material were determined. Theamount of expansion of the side part of the thermal insulating cabinetformed after removal from the mold was measured. These results are shownin Table 4.

Comparative Example 5

With respect to the case where glycidylamines are removed from the rawmaterial mixture of Example 7 (Comparative Example 5-1) and the casewhere glycidyl ethers are removed from the raw material mixture ofExample 7 (Comparative Example 5-2), a thermal insulating foamedmaterial was obtained in the same manner as stated above. With respectto the case where the formulation ratio of polyisocyanate was adjustedso that the amount of the NCO group becomes 0.95 equivalents perhydroxyl group in the polyol composition (Comparative Example 5-3) andthe case where the amount of the NCO group becomes 1.15 equivalents perhydroxyl group of the polyol composition (Comparative Example 5-4) inExample 7-2, a thermal insulating foamed material was obtained in thesame manner as stated above. In Comparative Example 5-4, the excess NCOgroups which are enough to be able to react with 50% or more of theepoxy groups in epoxides are formulated. The results of thesecomparative examples are also shown in Table 4.

                                      TABLE 4                                     __________________________________________________________________________                       Example     Comparative Example                                               7-1 7-2 7-3 5-1 5-2 5-3 5-4                                __________________________________________________________________________    Mixing                                                                             Glycidyl ethers                                                                             22.9                                                                              18.3                                                                              13.8                                                                              36.7    18.3                                                                              18.3                               ratio of                                                                           Glycidylamines                                                                              10.0                                                                              13.4                                                                              16.8    26.9                                                                              13.4                                                                              13.4                               solution                                                                           Carbon dioxide fixation                                                                     2.0 2.0 2.0 2.0 2.0 2.0 2.0                                D    catalyst                                                                 Epoxy ratio (Ea/Ee)                                                                              0.69                                                                              1.17                                                                              1.92                                                                              0   --  1.17                                                                              1.17                               Equivalent of NCO per hydroxyl group                                                             1.05                                                                              1.05                                                                              1.05                                                                              1.05                                                                              1.05                                                                              0.95                                                                              1.15                               Evaluation                                                                         one                                                                              Thermal conductivity                                                                     0.0169                                                                            0.0169                                                                            0.0170                                                                            0.0180                                                                            0.0185                                                                            0.0170                                                                            0.0180                             results                                                                            day                                                                              (W/mK)                                                                after   Gas    CO.sub.2                                                                          5   5   5   25  50  5   25                                 aging   composition                                                                          CP  95  95  95  75  50  95  75                                         (%)                                                                   one     Thermal conductivity                                                                     0.0170                                                                            0.0169                                                                            0.0169                                                                            0.0170                                                                            0.0175                                                                            0.0170                                                                            0.0170                             week    (W/mK)                                                                after   Gas    CO.sub.2                                                                          5   5   5   5   25  5   5                                  aging   composition                                                                          CP  95  95  95  95  75  95  95                                         (%)                                                                   Expansion amount of thermal                                                                      <3 mm                                                                             <3 mm                                                                             <3 mm                                                                             <3 mm                                                                             <3 mm                                                                             5-7 mm                                                                            <3 mm                              insulating cabinet                                                            __________________________________________________________________________

As is apparent from a comparison shown in Table 4, it becomes possibleto rapidly fix carbon dioxide remaining inside the closed cells and toincrease the ratio of cyclopentane as the volatile blowing agent withoutincreasing the resin thermal conductivity of the polyurethane foamedmaterial by using a mixture of glycidylamines and glycidyl ethers asepoxides, thereby to obtain a thermal insulating foamed material havingan excellent thermal insulating property. It is also possible to rapidlydevelop the mechanical strength of the thermal insulating foamedmaterial, thereby to improve the productivity.

In Comparative Example 5-1, it was possible to finally improve to thesame property as that of Comparative Example 7 in the same manner as inExample 3-1, but the productivity was drastically deteriorated.

In Comparative Example 5-2, the productivity was drasticallydeteriorated in the same manner as in Comparative Example 3-2.

In Comparative Example 5-3, the appearance and quality of the thermalinsulating cabinet were drastically deteriorated in the same manner asin Comparative Example 3-3.

In Comparative Example 5-4, the productivity was drasticallydeteriorated in the same manner as in Comparative Example 3-4.

EXAMPLE 8

A polyol composition comprising 100 parts by weight of polyether polyolhaving a hydroxyl group value of 500 (mg KOH/g), 1 part of a urethanereaction catalyst, 3 parts of a foam stabilizer, 15 parts of HFC245fa asthe volatile blowing agent and 1 part of a mixture of water and formicacid as the reactive blowing agent was prepared.

Epoxides for fixing carbon dioxide were obtained by mixing 4 parts of1,2-butylene oxide (epoxy equivalent: 72) as the epoxide compound havinglow reactivity with carbon dioxide and low reactivity withpolyisocyanate, 7.9 parts of glycidyl methacrylate (epoxy equivalent:142) and 6 parts of neopentyl glycol glycidyl ether (epoxy equivalent:108) as the epoxide compounds having a boiling point of more than 120°C. The molar amount of the epoxy group of glycidyl methacrylate andneopentyl glycol diglycidyl ether per mol of the epoxy group of1,2-butylene oxide is about one mol, respectively. The total amount ofepoxides corresponds to the amount containing the epoxy group of about 3mol per mol (stoichiometric amount) of carbon dioxide evolving at thetime of blowing.

Then, the epoxides were mixed with 15 parts of brominatedtetrabutylammonium as the carbon dioxide fixation catalyst. This mixedsolution, the above-mentioned polyol composition and 133 parts ofpolyisocyanate were mixed with stirring and the mixture was injectedinto the space part of a container produced by combining an inner linerwith an outer shell and blown.

Comparative Example 6

As epoxides for fixing carbon dioxide, a mixture of glycidylmethacrylate and neopentyl glycol diglycidyl ether was used. The amountof the epoxides added corresponds to the amount containing the epoxygroup of about 3 mol per mol (stoichiometric amount) of carbon dioxideevolving at the time of blowing. A thermal insulating cabinet wasprepared in the same manner as in Example 8 except for theabove-mentioned conditions.

The filling state of the thermal insulating foamed material into thethermal insulating cabinet was good in Example 8 and Comparative Example6. One day after blowing, the endotherm of the thermal insulatingcabinet of Example 8 and that of Comparative Example 6 was measured, andthe thermal insulating property was evaluated. As a result, the thermalinsulating property of both thermal insulating cabinets were superior byabout 5% to that of the thermal insulating cabinets prepared by addingno epoxides. The thermal insulating property of the thermal insulatingcabinet of Comparative Example 6 was improved by only about 2% with atime lapse, while the thermal insulating property was improved by about5% in Example 8.

The thermal insulating foamed material was analyzed. As a result, it wasfound that 1,2-butylene oxide having a boiling point of 63° C. wasvaporized at the time of blowing in Example 8 and, therefore, the sidereaction between it and polyisocyanate was inhibited. It was also foundthat after the fixation of carbon dioxide by glycidyl methacrylate andneopentyl glycol diglycidyl ether, 1,2-butylene oxide causes the carbondioxide fixation catalyst which exists in the foamed material to fixcarbon dioxide in the closed cells, thereby to form a carbonate and,therefore, the thermal insulating property is improved with a timelapse.

INDUSTRIAL APPLICABILITY

As described above, according to the present invention, it is possibleto obtain a thermal insulating foamed material, which is superior inthermal insulating property because of decreased amount of carbondioxide in closed cells and does not cause deterioration of the thermalinsulating property with a time lapse. According to the presentinvention, carbon dioxide inside the closed cells is rapidly fixed inthe production step and, therefore, a vapor thermal conductivity isimproved, thereby to improve the thermal insulating property of athermal insulating foamed material. At the same time, a mechanicalstrength of the thermal insulating foamed material is rapidly developedand, therefore, productivity is also excellent.

We claim:
 1. A thermal insulating foamed material comprising a foamedurethane resin composition having closed cells, said foamed urethaneresin composition containing a carbon dioxide fixation catalyst andcyclic carbonate compounds as products of reactions between carbondioxide and epoxides in the presence of said carbon dioxide fixationcatalyst, said cyclic carbonate compounds comprising at least twomembers of a reaction product of an epoxide compound, having highreactivity with carbon dioxide, and carbon dioxide and a reactionproduct of an epoxide compound, having low reactivity with carbondioxide, and carbon dioxide.
 2. The thermal insulating foamed materialin accordance with claim 1, wherein said epoxide compound having highreactivity with carbon dioxide is an epoxide complex in which saidcarbon dioxide fixation catalyst is coordinated to an oxirane ring. 3.The thermal insulating foamed material in accordance with claim 2,wherein said epoxide compound having high reactivity with carbon dioxideis an epoxide complex in which said carbon dioxide fixation catalyst iscoordinated to an alkylene oxide, and said epoxide compound having lowreactivity with carbon dioxide is an alkylene oxide.
 4. The thermalinsulating foamed material in accordance with claim 2, wherein saidepoxide compound having high reactivity with carbon dioxide is anepoxide complex in which said carbon dioxide fixation catalyst iscoordinated to an alkylene oxide, and said epoxide compound having lowreactivity with carbon dioxide comprises an alkylene oxide and aglycidyl ether.
 5. The thermal insulating foamed material in accordancewith claim 1, wherein said epoxides contain an epoxide compound havinghigh reactivity with polyisocyanate and an epoxide compound having lowreactivity with polyisocyanate, and said epoxide compound having lowreactivity with carbon dioxide is an epoxide compound having highreactivity with polyisocyanate.
 6. The thermal insulating foamedmaterial in accordance with claim 5, wherein said epoxide compoundhaving high reactivity with polyisocyanate is a polyglycidyl etherhaving two or more epoxy groups, and said epoxide compound having lowreactivity with polyisocyanate is a monoglycidyl ether having one epoxygroup.
 7. The thermal insulating foamed material in accordance withclaim 5, wherein said epoxide compound having high reactivity withpolyisocyanate is a polyglycidyl ether having at least one hydroxylgroup, and said epoxide compound having low reactivity withpolyisocyanate is a glycidyl ether having no hydroxyl group.
 8. Thethermal insulating foamed material in accordance with claim 5, whereinsaid epoxide compound having high reactivity with polyisocyanate is apolyglycidylamine, and said epoxide compound having low reactivity withpolyisocyanate is a glycidyl ether.
 9. The thermal insulating foamedmaterial in accordance with claim 1, wherein said epoxides contain anepoxide compound having a boiling point of more than 120° C. and anepoxide compound having low reactivity with polyisocyanate and a boilingpoint of 120° C. or less, and said epoxide compound having lowreactivity with carbon dioxide is an epoxide compound having lowreactivity with polyisocyanate.
 10. The thermal insulating foamedmaterial in accordance with claim 9, wherein said epoxide compoundhaving a boiling point of more than 120° C. is a glycidyl ether, aglycidyl ester or a glycidylamine, and said epoxide compound having aboiling point of 120° C. or less is an alkylene oxide.
 11. A method forproducing a thermal insulating foamed material, which comprises thesteps of:blowing a raw material mixture containing epoxides comprisingat least two members of an epoxide compound having high reactivity withcarbon dioxide and an epoxide compound having low reactivity with carbondioxide, a carbon dioxide fixation catalyst, polyisocyanate, a reactiveblowing agent which evolves carbon dioxide by reacting with saidpolyisocyanate, and a polyol composition, thereby to form a foamedpolyurethane resin composition having closed cells in which at leastcarbon dioxide is filled, and allowing said carbon dioxide in saidclosed cells to react with said epoxides in the presence of said carbondioxide fixation catalyst, thereby to fix carbon dioxide as carbonatecompounds.
 12. The method for producing a thermal insulating foamedmaterial in accordance with claim 11, wherein said raw material mixturefurther comprises a volatile blowing agent.
 13. The method for producinga thermal insulating foamed material in accordance with claim 11,wherein said epoxides have an epoxy group of 1 to 6 mol per mol(stoichiometric amount) of said carbon dioxide evolving by the reactionbetween said polyisocyanate and said reactive blowing agent.
 14. Themethod for producing a thermal insulating foamed material in accordancewith claim 11, wherein said polyisocyanate has an isocyanate group whosemolar amount is the same as that of a hydroxyl group in said rawmaterial mixture, and has an isocyanate group which reacts with 0 to 50%of said epoxy group of said epoxides.
 15. The method for producing athermal insulating foamed material in accordance with claim 11, whereinsaid epoxide compound having high reactivity with carbon dioxide is anepoxide complex in which said carbon dioxide fixation catalyst iscoordinated to an oxirane ring.
 16. The method for producing a thermalinsulating foamed material in accordance with claim 15, wherein a ratioof a molar amount of an epoxy group of said epoxide complex to a molaramount of an epoxy group of said epoxide compound having low reactivitywith carbon dioxide is from 0.01 to 1.0.
 17. The method for producing athermal insulating foamed material in accordance with claim 16, whereinsaid epoxide compound having high reactivity with carbon dioxide is anepoxide complex in which said carbon dioxide fixation catalyst iscoordinated to an alkylene oxide, and said epoxide compound having lowreactivity with carbon dioxide is an alkylene oxide.
 18. The method forproducing a thermal insulating foamed material in accordance with claim16, wherein said epoxide compound having high reactivity with carbondioxide is an epoxide complex in which said carbon dioxide fixationcatalyst is coordinated to an alkylene oxide, and said epoxide compoundhaving low reactivity with carbon dioxide comprises an alkylene oxideand a glycidyl ether.
 19. The method for producing a thermal insulatingfoamed material in accordance with claim 11, wherein said epoxidescontain an epoxide compound having high reactivity with polyisocyanateand an epoxide compound having low reactivity with polyisocyanate, andsaid epoxide compound having low reactivity with carbon dioxide is anepoxide compound having high reactivity with polyisocyanate.
 20. Themethod for producing a thermal insulating foamed material in accordancewith claim 19, wherein a ratio of a molar amount of an epoxy group ofsaid epoxide compound having high reactivity with polyisocyanate to amolar amount of an epoxy group of said epoxide compound having lowreactivity with polyisocyanate is from 0.50 to 2.0.
 21. The method forproducing a thermal insulating foamed material in accordance with claim20, wherein said epoxide compound having high reactivity withpolyisocyanate is a polyglycidyl ether having two or more epoxy groups,and said epoxide compound having low reactivity with polyisocyanate is amonoglycidyl ether having one epoxy group.
 22. The method for producinga thermal insulating foamed material in accordance with claim 20,wherein said epoxide compound having high reactivity with polyisocyanateis a glycidyl ether having at least one hydroxyl group, and said epoxidecompound having low reactivity with polyisocyanate is a glycidyl etherhaving no hydroxyl group.
 23. The method for producing a thermalinsulating foamed material in accordance with claim 20, wherein saidepoxide compound having high reactivity with polyisocyanate is apolyglycidylamine, and said epoxide compound having low reactivity withpolyisocyanate is a glycidyl ether.
 24. The method for producing athermal insulating foamed material in accordance with claim 11, whereinsaid epoxides contain an epoxide compound having a boiling point of morethan 120° C. and an epoxide compound having low reactivity withpolyisocyanate and a boiling point of 120° C. or less, and said epoxidecompound having low reactivity with carbon dioxide is an epoxidecompound having low reactivity with polyisocyanate and a boiling pointof 120° C. or less and, further, a ratio of a molar amount of an epoxygroup of said epoxide compound having a boiling point of more than 120°C. to a molar amount of an epoxy group of said epoxide compound having aboiling point of 120° C. or less is from 0.20 to 2.0.
 25. The method forproducing a thermal insulating foamed material in accordance with claim24, wherein said epoxide compound having a boiling point of more than120° C. is a glycidyl ether, a glycidyl ester or a glycidylamine, andsaid epoxide compound having a boiling point of 120° C. or less is analkylene oxide.
 26. A thermal insulating cabinet comprising an outershell, an inner liner and a thermal insulating foamed material filled inthe space part formed by said outer shell and said inner liner, saidthermal insulating foamed material comprising a foamed urethane resincomposition having closed cells, said foamed urethane resin compositioncontaining a carbon dioxide fixation catalyst and cyclic carbonatecompounds as products of reactions between carbon dioxide and epoxidesin the presence of said carbon dioxide fixation catalyst, said cycliccarbonate compounds comprising at least two members of a reactionproduct of an epoxide compound having high reactivity with carbondioxide and carbon dioxide and a reaction product of an epoxide compoundhaving low reactivity with carbon dioxide and carbon dioxide.